Bump actions/setup-python from 5 to 6

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 5 to 6.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/build-docs.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Set up Python 3.9
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: 3.9
 

.github/workflows/python-publish.yml

@@ -18,7 +18,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.x'
 

.github/workflows/python-test.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
 
@@ -72,7 +72,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: "Setup Python"
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: 3.9